The objectives of this project are to support the organization of the National Temporal Bone Rank Center (NTBBC) initiated in 1960 by the combined efforts of the Deafness Research Foundation in New York (DRF) and the American Academy of Ophthalmology and Otolarynogology (AAOO). The NTBBC received its initial support from the DRF. The activities of the NTBBC include: 1) to assist in a decisive manner in the solicitation of new pledges of temporal bones from individuals with carefully selected and otologically well documented disease entities affecting hearing and equilibrium; 2) to maintain a 24 hour service concerned with the collection of pledged temporal bones and medical information; 3) to distribute the collected temporal bones to the respective affiliated Temporal Bone Pathology Laboratories for processing and microscopic analysis; 4) to request from these Laboratories that a duplicate set of these serially sectioned temporal bones are forwarded to the Armed Forces Institute of Pathology (AFIP) for the National Collection; 5) to organize bienially a conference for laboratory directors for exchange of technical and scientific information and outline the center's future activities; and 6) to disseminate important and recent information to scientific investigators in regional research laboratories and to the nation's central institute of pathology.